Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"Many degrees of freedom"”.
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Nonlinear resonances in systems having many degrees of freedom
An analysis is presented of the main, superharmonic, subharmonic, combination and internal resonances in a weakly nonlinear system having many degrees of freedom. The system has cubic nonlinearities, modal linear viscous damping and is subject to harmonic excitations. The method of multiple scales, …
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Characterising intra- and inter-limb gait stability using minimum foot clearance
… aging effects by characterising one parameter of the gait cycle from treadmill walking. The minimum foot clearance (MFC) during the swing phase of gait is an essential event that reveals two things: 1) how the locomotor system achieves control over many degrees of freedom when performing this …
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Reduction of computational effort in structural dynamics calculations
The time-history analysis of realistic structures can often be computationally quite expensive. The main reason for the high volume of computation is the fact that the time interval must usually be very small. The factors that limit the time interval fall into three categories: (1) The input may …
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Sensitivity analysis on chaotic dynamical systems by Non-Intrusive Least Squares Shadowing (NILSS)
… a tangent solution by a linear combination of one inhomogeneous tangent solution and several homogeneous tangent solutions. Next, we solve a least squares problem using this representation; thus, the resulting solution can be used for computing sensitivities. NILSS is easy to implement with …
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Jacobian-based control of soft robots for manipulation using implicit surface models
Soft robot hands offer numerous advantages over rigid ones for manipulation, including robustness and safety. Yet, compared to rigid robots, soft robots are characterized by continuous mechanics, and finite-element approximations with many degrees of freedom present a significant obstacle for …
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Sensory modulation of muscle synergies for motor adaptation during natural behaviors
… central nervous system (CNS) must coordinate the many degrees of freedom in the musculoskeletal apparatus. It has been suggested that the CNS simplifies this formidable task of coordination by grouping multiple muscles together into units of activation, or muscle synergies. Previous studies have …
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Safe and Efficient Motion Planning through Chance-Constrained Nonlinear Optimization
… for robots deployed in the real world. Outside of a carefully-structured laboratory environment, neither the locations of obstacles nor the true state of the robot can be known with perfect certainty. This makes planning safe maneuvers challenging, particularly for robots with many degrees of …
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Adaption of performed ballistic motion
… method for adapting performed ballistic motions of a full human figure with many degrees of freedom by using an optimal trajectory formulation and the dynamics derived from first principles. Computation of the joints, torques, and reaction forces allows the application of a number of optimization …
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Modular robots for making and climbing 3-D trusses
… robot has been extensively investigated because of its wide range of promising applications such as construction and inspection of truss structures. It is designed to have degrees of freedom to move in three-dimensional truss structures. Although many degrees of freedom allow the robot to reach …
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Reinforcement Learning and Planning for Preference Balancing Tasks
Robots are often highly non-linear dynamical systems with many degrees of freedom, making solving motion problems computationally challenging. One solution has been reinforcement learning (RL), which learns through experimentation to automatically perform the near-optimal motions that complete a …
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Non-inertial Undulatory Locomotion Across Scales
… In particular, undulatory locomotion is one of the most common forms of locomotion. From microscopic flagellates to swimming fish and slithering snakes, this form of locomotion is a remarkably robust self-propulsion strategy that allows a diversity of organisms to navigate myriad …
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Waveform Diversity and Range-Coupled Adaptive Radar Signal Processing
Waveform diversity may offer several benefits to radar systems though often at the cost of reduced sensitivity. Multi-dimensional processing schemes are known to offer many degrees of freedom, which can be exploited to suppress the ambiguity inherent to pulse compression, array processing, and …
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Optimisation of Gaussian process regressions of molecular potential energy surfaces
… some fundamental questions on the importance of the mathematical expression of the feature dimensions of the input space. Moreover, for Gaussian processes which are particularly popular in regression problems, the choice of an appropriate kernel function to construct the desired model is not …
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Brownian dynamics simulations of fine-scale molecular models
One of the biggest challenges in non-Newtonian fluid mechanics is calculating the polymer contribution to the stress tensor, which is needed to calculate velocity and pressure fields as well as other quantities of interest. In the case of a Newtonian fluid, the stress tensor is linearly …
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Discrete Sparse Fourier Hermite Approximations in High Dimensions
… discrete sparse Fourier Hermite approximation of a function in a specified Hilbert space of arbitrary dimension is defined, and theoretical error bounds of the numerically computed approximation are proven. Computing the Fourier Hermite approximation in high dimensions suffers from the …
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A Dynamic Primitives Hypothesis: a Descriptive Model of Human Physical Interaction
Physical interaction is a key aspect of activities of daily living. These tasks require simultaneous regulation of both force and motion. For example, even a task as simple as opening a door presents a challenge to the development of prosthetics, exoskeletons, and human-robot interaction. Motor …
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Der Einsatz von Simulationen zur Untersuchung von Fehlereinflüssen in der Interferometrie
The knowledge of measurement uncertainties is an elementary requirement for the proper assessment of product-quality and for controlling production processes. Furthermore, the determination of measurement uncertainties is essential to ensure the comparability with other types of metrological …
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Thermodynamic and topological characterization of living systems
… to study the growth, dynamics, and response of complex biophysical systems at single-cell and subcellular resolution, from bacterial communities and tissues to intra-cellular signaling and expression dynamics of genes. Despite such progress in data collection, major theoretical challenges …
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Human physical interaction with a circular constraint
Despite large feedback delays, and many degrees of freedom, humans are incredibly dexterous and excel at physical interaction with complex objects. In this work we developed an upper limb crank turning experiment to study the human controller used to manage physical interaction. Subjects turned a …
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Feedback Control Theory in Stochastic Dynamical Systems
… stochastic dynamical system is a system composed of many interacting components which includes stochastic behavior. Feedback control theory is designed to use information from the current state of the system in order to temper the final state toward the desired outcome. In this dissertation, I …
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